zschaefer38

Need to replace them both for preventative maintenance. Want to order the right ones. I was told that Merc stopped making the greasable ones and that I should go to Sierra. Part numbers anybody?

waconda

The grease-able one had a service life of 2500 hrs and the seal ones are 10000 hrs. Most people put in the wrong grease anyway.

apollard

Having a greasable bearing in mine now, what is considered the 'right' grease. What Merc recommends for it in the '94 manual isn't available.

proboat-wes

sierra# 18-2100
i dont believe theres a lifetime lubed bearing.grease is the life of anything that moves.if thats not the case why dont we just leave the oil in our boat forever?? mercruiser u-joint and gimbal bearing grease is what ill always use.pretty resistant to moisture

zschaefer38

There is my confusion. I have had people say 18-2100 and 18-21005?

proboat-wes

you can run the 18-2100 or the 18-21005 0n older bravos and alpha gen 2 drives.. if you have a late model bravo serial number OF730000 and above or xr drives you need to run the 18-21005.the inner race lip that touches the end of the drive shaft closest to the u-joint end has been machined down a couple of thousands so as not to bind under full negative.hope this helps

zschaefer38

Thanks for the insight. Is it true that the 18-21005 is also more "heavy duty"? I have had two people, including yourself, tell me to use the 18-21005. Ebay has them for 60 bucks a piece with shipping.....

proboat-wes

no more heavy duty than the other.also the gimbal bearing is rarely the weak link unless it has been full of water or not maintained regulary,wes

zschaefer38

Ohh it's a weak link. Just bought the boat and the surveyor said the port one is bad. After yanking the drives there must be a bad bellow at one time or now because it looks fairly nasty up in there and my U joint on the drive has some surface rust not pitted. So I am replacing both bearings and replacing u joints on the port drive.